FH (4) Select section FH (4) Volvo: Function group: 177. Bogie oil 177. Coolant 177. Engine oil 177. Gearbox oil 177. Hydraulic oil, servo 177. Rear axle oil (forward rear, driven) 177. Rear axle oil (rear driven) 177. Rear axle oil (rear rear, driven) 177. Retarder oil